The present invention is directed to container and closure packages that resist opening by a child, and more particularly to a container and a closure for such a package, and to a method of manufacturing such a package, container and closure.
A number of child resistant container and closure packages have been proposed in the art. In general, these packages require simultaneous application of force in two directions in an effort to defeat opening by a child. However, opening of the packages should not require excessive force or dexterity, so that the packages can be opened by elderly or infirm persons. It is a general object of the present invention to provide a child resistant container and closure package, a container and a closure for such a package, and a method of making such a package, container and closure, which may be implemented inexpensively and that require minimal application and removal force.
A child resistant container and closure package in accordance with the present invention includes a container of one-piece integrally molded plastic construction having a cylindrical finish, a shoulder connecting the finish to a side wall, a ring externally extending around the finish, and a tab extending from the ring and separated from the finish by a tangential slot. A stop lug on the tab has oppositely oriented stop and cam faces, and at least one rib extends tangentially along an undersurface of the tab. A closure has a base wall with a peripheral skirt and an internal thread for securement to an external thread on the container finish. At least one internal lug on the skirt has a circumferentially oriented cam surface to cooperate with a cam surface on the stop lug on the container tab to bend the stop lug as the closure is applied to the container finish, and a circumferentially oriented abutment surface to cooperate with the stop face on the container stop lug against removal of the closure from the container finish absent depression of the container tab toward the container shoulder. The rib extending tangentially along the undersurface of the tab functions both to strengthen the tab during such depression and as an abutment stop against the container shoulder during bending depression of the tab to remove the closure.
In one preferred embodiment of the invention, there are a pair of parallel radially spaced ribs extending along the underside of the tab onto the underside of the ring that impart an inverted U-shaped cross section to the tab and to the ring adjacent to the tab. In another preferred embodiment, there is a single rib extending along the radially inner edge of the tab, imparting an L-shaped cross section to the tab. The stop lug on the tab in the preferred embodiments has an axially and tangentially extending first cam face, and a radially and axially extending second cam face for cooperating with the internal lug on the closure to cam the internal lug over the stop lug. The cam surface on the internal lug preferably is a compound surface having portions oriented tangentially, radially and axially of the closure for camming the stop lug on the container radially inwardly and axially downwardly as a closure is applied clockwise onto the container finish.
A child resistant container in accordance with another aspect of the invention is of one-piece integrally molded plastic construction having a sidewall, a cylindrical finish with an external thread and a shoulder connecting the sidewall to the finish. A ring extends circumferentially around the finish between the thread and the shoulder, and a tab extends tangentially from the ring and is separated from the ring by a tangential slot. A stop lug extends from the tab, and has oppositely oriented stop and cam faces. At least one rib extends tangentially along an undersurface of the tab. This rib functions both to strengthen the tab and as an abutment stop for bending depression of the tab toward the shoulder. In one preferred embodiment, there are a pair of parallel radially spaced ribs extending along the undersurface of the tab onto the underside of the ring and imparting an inverted U-shaped cross section to the tab and to the ring adjacent to the tab. In another preferred embodiment, there is a single rib extending along the radially inner edge of the tab, imparting an L-shaped cross section to the tab. The stop lug preferably has an axially and tangentially extending first cam face, and a radially and axially extending second cam face for cooperating with an internal lug on a closure to cam the stop lug and tab axially downwardly and radially inwardly with respect to the container finish.
A closure for a child resistant package in accordance with a further aspect of the invention has a base wall and a peripheral skirt with an internal thread for securement to the container finish. At least one internal lug is disposed on the skirt on a side of the thread remote form the base wall. The lug has a circumferentially oriented cam surface and a circumferentially oriented abutment surface. The cam surface on the lug preferably is at a compound surface having portions oriented tangentially, radially and axially of the closure. In the preferred embodiment, there are a pair of diametrically opposed internal lugs on opposite sides of the closure skirt.